World Heritage-listed Henderson Island in Pitcairn Group has an estimated 17.6 tonnes of plastic debris

By Dani Cooper

MELBOURNE, Australia (Radio Australia, May 16, 2017) – A remote and uninhabited island wilderness in the South Pacific is literally a garbage dump.

The beaches of World Heritage-listed Henderson Island, in the Pitcairn Group off South America, contain an estimated 37.7 million items of debris together weighing 17.6 tonnes, a new study has revealed.

Australian researcher Dr Jennifer Lavers said it meant the island had the highest density of plastic rubbish anywhere in the world.

She said the finding, published today in the Proceedings of the National Academy of Sciences, was a wake-up call to the world that plastic pollution was as grave a threat to humanity as climate change.

Annual production of plastic has increased from 1.7 million tonnes in 1954 to 311 million tonnes in 2014.

This has resulted in an estimated five trillion plastic items — mostly less than five millimetres in size — circulating in the surface layer of the world's oceans.

To understand how much debris was accumulating on the remote island, Dr Lavers, a conservation biologist at the University of Tasmania's Institute for Marine and Antarctic Studies, and Dr Alexander Bond at the Centre for Conservation Science in the UK surveyed the island's North and East Beach for three months in 2015.

Dr Lavers said the 17.6 tonnes of plastic debris estimated to be on Henderson Island accounted for just 1.98 seconds' worth of the current annual global production of plastic.

She said the amount of rubbish was such that it took a five-person team six hours to survey a 10-metre section of the beach.

The team calculated there were 671.6 items per square metre on the surface of the beaches, with approximately 68 per cent of debris buried less than 10 centimetres in the sand.

Each day, 17 to 268 new items washed up on a 10-metre section of North Beach, representing a daily accumulation rate of 1.7 to 26.8 items per metre.

The scale of the pollution at Henderson Island shocked Dr Lavers, despite a career visiting many ocean "garbage patches" and tracking plastic pollution in marine environments.

"In addition to just blowing my mind with the sheer volume of plastic that was there, what amazed me was the majority of the debris was not shipping waste," she said.

Henderson Island is in an area of the ocean that is rarely traversed and is not near any shipping lanes or fisheries, with no major land-based industrial facilities or cities within 5,000 kilometres.

The nearest settlement is Pitcairn Island with a population of 40 people.

Everyday items make up bulk of garbage

Dr Lavers said only around 7 per cent of the junk on the beach was connected to fishing-related activities.

She said most of the items found on the beaches were everyday household items such as cigarette lighters, plastic razors, toothbrushes, plastic scoops used in detergents or baby formula, and babies' dummies.

Dr Lavers said their study showed "there is nowhere left in the world that is safe — plastic is ubiquitous".

Just over a quarter of the rubbish came from South America and was the result of the movement of currents in the South Pacific gyre, which flows anti-clockwise after travelling north up the continent.

The estimates were "alarmingly" conservative, as the survey did not include items buried deeper than 10 centimetres or debris on cliff areas or rocky sections.

Plastic pollution was a major threat to marine species, Dr Lavers said, with a study released in the past two months suggesting about 1,200 species were negatively impacted.

On Henderson Island the rubbish created a barrier for sea turtles attempting to enter the beach and led to a reduction in sea turtle-laying numbers, while also affecting two native seabird species.

However, Dr Lavers said plastic pollution was also a major threat to human health as the toxic impact of plastic-related chemicals in the food chain were well documented.

"At a very minimum, 25 per cent of world's marine fish species are consuming plastic and we know with that plastic comes a suite of chemical pollutants," she said.

"Those fish are the base of the food web ... and we know humans are at the top of the food web.

"It is not a big leap to say the whole of the marine food web is contaminated and we are putting ourselves at grave risk."

Dr Lavers said the solution was a broad, sweeping education campaign and societal change, driven by public demand.

"Politicians don't make decisions based on what scientists say — when decisions are made it is because the public demands it," Dr Lavers said.

"That won't happen until the whole of the population recognises that this is the equivalent of climate change. We need to move now and we need to move fast.

"I need the public to give me their voice [for] a global movement, so we can break our plastic addiction here and now."

Pacific Islands Report is a nonprofit news publication of the Pacific Islands Development Program at the East-West Center in Honolulu, Hawai‘i. Offered as a free service to readers, PIR provides an edited digest of news, commentary and analysis from across the Pacific Islands region, Monday - Friday.